Gauge glass illuminating device



April 18, 1939. J. McCLAlN 2,154,819

GAUGE GLASS ILLUMINATING DEVICE Filed Aug. 22, 1936 v INVENTOR -LTUHN MEELFHN.

w/ 7 555. A TTORNE Y Patented Apr. 1939 UNITED STATES PATIENT OFFICE 1 GAUGE GLASS naumm'rnve navrca Ioh mcmn, 111.

Application August 2a, 1936, swarm. 67,04

8Claims.

Manyeattempts have been made to provide.

1 means for distinguishing the liquid level 'in the glass. Much of this priorart is directed to placing a colored background of distinctive 'pattem 15 behind the glass, the liquid in the glass acting as a lens to magnify the pattern in the background,, thereby distinguishing from the empty portion of the glass. This type of attachment has two principal disadvantages; One is, that boiler.

20 gauge glasses become dirty rather quickly and then any type of background is indistinguishable is, that those devices in the prior art which consist of background distinguishing means, are 5 fixed either to the gauge glass itself, or to its fittings. As the gauge glass is one of the weak-- est points in a steam boiler, it is desirable that the au e glass be free from all irregularities in its construction andfrom attachments after its so installation. Consequently, many steam 'boiler engineers object to any devices attached to the gauge glass or to its iittings. i

In order to avoid the, first mentioned disadvantage of background distinguishing devices,;

as other devices have been designed which function on the principle of directing light through the gauge glass. This principle, while it is more ef-' reactive than mere background plates, does not entirely avoid this objection, because as a gauge 9 glass approaches a nearly translucent' condition,

(many glasses actually exist in this condition in daily operation), even distinctive light patterns v become rather obscure, making it diflicult' to uickly pick out the liquid level in the glass. 5 Deviceshave been produced which avoid this diiiiculty byusing the diflernt indices of refraction in liquidv and in steam, or two different liquids. to transmit light from sources of different ooiors through thewater and the steam. Such a device is. however, complicated and,ex'pensive.

- The principal object of the present invention is to provide a simple and inexpensive device for distinguishing the level of liquid in a gauge glass,

h or clean," is Wobieotisto-providea cswhich of whether the glass is that the'level o! colorless is separate from and independent of the gauge glass and its fittings.

A further object is to provide a device for this purpose, which can be installed with existing gaugeglasses, and which requires little space 5 so that it may be installed between the gauge glass and the water column.

In accomplishing these objects, I have recognized that even in the case of glasses which are so dirty and discolored as to be practicalLv trans- 1o lucent,- although, no pattern of background or ,even distinctive pattern of-light could be seen through the glass, the difierence between light and dark can always be distinguished.

Hence it is another object of my invention to 15 produce a device which will cause that portion of the glass containing liquid ,to appear dark, and that portion above the liquid level to appear bright. v p

Qther objects will become apparent to those.,2o

' skilled in the art after a consideration of the folthrqugh the glass from'a distance. The other which the device is adjusted for viewing it from a different angle Figure 4 is an elevation of a. lamp and opaque hood;

Figure 5 is a fragmentary elevation of a W 35 glass showing the appearance thereof at the water leveliiected by a device of the present invention; Figure 6 shows another embodiment of win-- vention in elevation;

Figure 7 is a section taken along' a line 1-1 in Fig. 4; and 7 Figure 8 is an end view of the hood. 1 Inthe drawing and specification like numerals refer to like parts throughout.

Referring now to Figure 1, reference numeral l indicates a water col having flanged'open ingsv 2 adapted for connection to aiboiler A gauge glass 3 of conventional type is supported between two'valve fittings, 5, respectively, with to conventional protecting tie-rods 6 extending vertically in front of the glass 3. 7 Conventional blowofl. cocks are indicated at I.

A gauge glass illuminating device, indicated.

"s isasio .disposed adjacentto the gauge glass 3, and com'- supporting member I. 'In the .case of prises .a long tubular electric lamp ll, preferexisting installations of gauges on boilers. etc..-

ably of theincandescent type although it may- 4) which cooperates with and is supported in a socket l3. The socket has a threaded stem H which is fitted with a lock nut It. The socket issupported on asupporting member it which is generally horizontally disposed and slightly curved, and has a slot l'l extending longitudinally thereof, the slot being also curved in a horizontal plane. The slot is adapted to receive the stem ll of the socket, which extends through the slot and is engaged by the nut)", firmly tightened to hold'the socket upright on the member I6. When the nut I5 is loosened, the socket canbe moved along the slot for purposes of adjustment.

A suitable insulated cord 23 connects the socke I! with a source of current.

The supporting member I is pivoted at one end to a bracket l8 by a pivot bolt II, which can the lamp, or it can be a heat-resisting coating on thelamp itself of enamel or the like. A. pair ofparailel elongated openings or slots 2! in the. hood 12! extend longitudinally, leaving an opaque strip -covers so Ahovethe 75 glass {that are made possible by meansof the having two slots longitudinally ofssid ll in-the center, which is preferably wide enough to cover the filament, thereby preventing glare.

The eii'ect of the parallel slots when viewed throug the gauge glass is illustrated in Figure 5.

Below acts asalenstomlgnify theimage ofthecenter strip 28 in the hood. By suitably proportioning the sizes of the slots 28 and strip li and the disstance between the glass 8 and the lamp ii, the image of the strip ll can be .so magnified that it the entire width of the glass 3, making that'portion (If-the glass dark. That is to say, the light directed through the slots 26 falling upon the glass I is refracted out and away from s. tof view in line-wi the glass and lamp, therefore that portion of the glass gm.

dark... As indicated in the drawing, the total that'alloftheli'ghtraysfromthelamp received at the point of view passed throimhflie mm "glasstubelistodiminishthesiseoftheslots 2] and strip 18, thereforethe two light-directing slots appear as parallel lines pf li ht as ilhis-' trated. It is now evident that even though the esaieeeb verydirmmeupper portion o'ftheglass willavp a brishtwhilethelowerportionofthe glass. underthe water level/will appearjdark;

Furthermore, when the tube is empty the'entire tube will appear-bright, thus giving a positive @70 indication of a condition ,that' is often dangerous,

to callattention to a lowwater'levelin a '8 liquid level 2!, the liquid in the glass indicate some ofthe the hood. Eelt. spacers it in the form of long there is very little space available'between glass 3 and the water column i, too small in fact, to receive most conventional ill devices. ms to be noted that the bracket II and the strap bolt 22 are spaced from the gauge glass 3, while the supporting member it extends through the space between the glass and-the column to support the lamp directly behind the the column, by pivoting the member IG- in the bracket [8, and by moving the socket il in theslot H, a wide range of adjustment 'of the lamp relative to the glass maybe obtained to obtain the proper focus and the proper angle of vision.

Figure 6 shows how another adjustment may I beincorporated for adjusting the angle of the device it with the vertical. Here the glass I is set at an angle in accordance with common practice. An additional extension member 3. is fastened to the supporting member it by a bolt II disposed within the slot II. The member II has an end :2 that isbent into a vertical plane to which asmall angle piece, 33 is pivoted by a bolt 4 S l -to which piece the socketris secured. In.

embodiment besides the adjustments dacribed tilation between the lamp and the hood. The

hood 2! is made with an internal diameter some- .of inclination of'the gauge what greater than the diameter of the lamp ll,

thus providinga space 38 between the hood and the lamp, which extendsvertically to the top of strips, extending substantially the full length of the hood, determine the position of the'hood and and contraction .of the lamp and hood and also.

absorb shocks received by the hood to preventbreakage of the lamp. The chimney eifect of the air space ll prevents overheating. Cold air is admitted to the space at the bottom end efine hood andrises to the topof the hood where it escapes through a'scre'en ll (l'igured) which is provided at the upper end of the tubular hood for protection of the lamp all-inst breakage.

menisedsssiiieeireeteitiieeinptr' except-as set forth in thefollowing 1:;An' illuminating device fora gauge glass,

I do notintendmy invention to be limited to theprecise' details shown..anddescribed'herein claims.

'I'claim: f.

said device comprisingin combination, a tubular lamp, an opaque hood therefor, said hood having -a plurality of longitudinally disposed parallel slots,fand means for supporting said p par-- allel toandadjsoent said sause glass. th width of the slotted portion. of said hood being" no ggaster than the outsidediameter of asid -gauge gated, lamp, an opaque hood therefor, said hood.

hood with an opaque strip between said slots,

slots being equal to, or less than the diameter of said gauge glass, and means for supporting said lamp parallel to and adjacent said gauge glass with said opaque strip interposed between said lamp and said gauge glass, said supporting means including means for adjusting the position of said lamp relative to said gauge glass.

3. 'An illuminating device for a gauge glass, said device comprising in.. combination, an elongated lamp, an opaque hood therefor, said hood having two slots extending longitudinally of said hood with an opaque strip between said slots, and means for supporting said lamp parallel to and adjacent said gauge glass, said supporting means including means for adjusting the distance between said lamp and said glass, to produce a magnified image of said opaque strip, as viewed through liquid in said gauge glass, that is substantially as wide as said glass, the width and spacing of said slots'being such that the latter are disposed within the width of said gauge glass.

4. In combination with a water column having a gauge glass inclined with respect to said column and supported in fittings in communication therewith, an elongated tubular lamp disposed adjacent said gauge glass, a socket member for supporting said lamp, an extension member adjustably fixed to said socket member by horizontal pivot means, an elongated curved horizontal supporting member having a slot, means slidable within said slot for adjustablysecuring the extension member to said supporting member, a bracket member, means for securing one end of said supporting member to said bracket member, said securing means providing adjustment of said lamp toward and away from said gauge glass,

and strap means embracing said water column for securing said bracket thereto.

5. In combination with a water column having a gauge glass inclined with respect to said column and supported in fittings in communication therewith, an elongated lamp disposed adjacent said gauge glass, a hood for said lamp providedwith light-directing openings therein, a socket member for supporting said lamp, an extension member adjustably fixed to said socket member by horizontal pivot means, an elongated curved horizontal supporting member having a slot, a bracket member, means for pivotally securing one end of said supporting member to said bracket membe and strap means embracing said water column the distance between the outer edges of said for fixing said bracket thereto, means slidably adjustable within said slot for adjustably securing the extension member to said supporting member, and said supporting member being angularly adjustable on said bracket toward and away from said gauge glass, to setthe lamp parallel to said gauge glass at the proper distance from the glassto produce an optical effect when viewed from a predetermined angle, which distinguishes that portion of said 'glass filled with liquid.

6. A gauge glass illuminating device comprising in combination, an elongated lamp, and a hood therefor, said hood having light-directing openings adaptedto direct light upon one side of said gauge glass in such manner that substan-'.

tially all of said light falling upon said'glass below the level of liquid therein is refracted away from a predetermined point of view at I the opposite side of said glass while light falling above said liquid level is transmitted through said glass to said point of view, said openings being of suitable width and spacing, whereby all direct rays of light from the lamp to said point of view pass through said glass.

'7. An illuminating device for a gauge glass, said device comprising in combination, a tubular lamp, a light restricting enclosure therefor, and, means for supporting said lamp substantially parallel tothe gauge glass on the opposite side thereof relative to a predetermined point of view, there being a plurality of light transmitting strips in said enclosure extending parallel to said gauge glass, said strips being disposed entirely within the width of said gauge glass.

8. An illuminating device for a gauge glass, said device comprising in combination, an elongated lamp, a light interrupting enclosure therefor, and means for supporting said lamp parallel to and adjacent said'gauge glass, there being two light transmitting strips in said enclosure extending longitudinally thereof and spaced apart with a light interrupting strip therebetween, the distance between the outer edges of said light transmitting strips being equal to, or less than the diameter of said gauge glass, whereby, when viewed from a certain point of view, the gauge glass entirely covers the light transmitting strips in the enclosure.

JOHN McCLAIN. 

